Why ANONYMOUS LOGON when printing?

This is the situation:
In one domain (RED), there is a domain admin (Printboy) that is logged on and scheduling print jobs in a different domain (BLUE). If 10 jobs are scheduled, most of the time Print Status will show "Printboy" as the user; but sometimes, "Anonymous Logon" will be listed as the user. There seems to be no rhyme or reason. The print server is the (BLUE) domain BDC; the user "Printboy" is a domain admin in both domains; and the print schedulng service is using the "Printboy" domain account. Sometimes, the scheduled jobs simply don't print. No event info, no errors, and no clue! Any help would be greatly appreciated.